The Rocky Mountains Are in the Wrong Place
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- Опубліковано 27 вер 2023
- Mountain ranges usually don't form in the middle of continents. Except for the Rocky Mountains. We'll go into the baffling Laramide Orogeny and a few possible reasons why the Rockies might be in the wrong place.
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Sources:
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If an orogeny is a mountain building event, then are the areas where mountains start to exist called orogenous zones?
subduction leads to orogeny......
Geology humor is so dirty...
Damnit. You got to the joke faster than I did. 😂
BY definition.
Literally yes! That's what they're called.
Usually as a joke. But the best jokes are the ones that are serious.
Considering we've only been at this tectonic science for less than 60 years I think we're doing a pretty darn good job.
I mean… we’re still debating a major part of it lol…
Yeah, if you're a betting man, you're probably at about 1 out of a 100, which is only 99 more to go. Some day, my friend, some day.
Who knows, maybe aliens messed with the evolution of orogeny and put their skinny thumb on the scale.
“We?” 🤣😆
I failed 8th grade science.
@@gavinsheridan4680"We" as in the collective human species. :P
@@drycleanernick7603 The most interesting science is usually the stuff we know the least about.
Studied geology at University of Colorado, so naturally the rockies were a pretty major topic and we did many labs out in the mountains. The prevailing theory for the laramide orogeny (and its location) taught at the time was the bouyant oceanic crust theory that you described towards the end. It was also why we the high planes have such a high elevation. The issue with volcanoes to the west wasn’t a concern since a wet oceanic crust creeping under the continental crust and resulting steam/magma could exploit weaknesses in the crust and create hot spots which would produce volcanoes regardless of any mountain building event. This was 15 years ago though, so take that with a grain of salt as i’m relying on memory, and certainly new data has emerged since.
People like you are why I love the Internet.
Not a geologist, just a guy who likes science, but couldn't does that theory HAVE to form volcanoes. Could it be different enough with the shallow angle so as to express the normal volcanic formations as geothermal hot springs instead? I've noticed there are definitely a higher concentration of hot springs in that area compared to other locations.
It happened during and after Pangea. The mass moving of continents made the Rockies. It's pretty obvious.
What about the blue hills mountains in wisconsin?
Will the grain of salt be from the subducted oceanic plate or from evaporites of the ancient inland sea?
My dad had a remote lodge in Alaska. To get there we flew through a pass in the Alaska range. There is a mountain that one side is a sheer face. You can see all the ribbon of layers of rock pushed, folded, and rippled, along its sheer face. It has always fascinated me. It looks like clay that hasn'tbeen kneeded for long. When you cut a side off. The swirls. Same thing but, on a masive scale. Those mountains make you feel minuscule. And in comparison I was.
I saw this area 100s of times. It was always engaging. Even now decades later I still think about it.
The American tectonic plates got confused because the instructions used the metric system.
Yes
"The [Canadian] tectonic plates got confused because the instructions used the [imperial] system."
😂😂😂😂
Only three country in the world use the irrelevant imperial system… so yeah…
So it's Jimmy Carter's fault?
Can't recommend enough the lecture on Rocky Mountain formation by Nick Zentner (can be found on UA-cam). He goes in depth into the new data from seismic tomography about the weird stuff going on under the North American continent. The Rocky Mountains may actually be the result of a continent-continent collision between North America and an immobile island arc in the prehistoric Pacific, making their formation more similar to the Himalayas!
I just linked it for the team. I've said Nick needs to be on Tangents
Zentner is great!
Nick is a legend!
@@stevexracer4309 Oh yeah? Do go on.
Last Winter's A-Z series is a must watch.
I was under the impression that the continent west of the rockies is mostly new stuff that just got piled onto the edge of the continent as the farillon plate slipped under north america. Anything sitting on top of tje playe just got smunched and stacked and piled up against each other, hence all the parallels ranges in Nevada. Then a different process takes over and you get all the crazy fault lines of CA. I remember seeing that Mt Diablo CA used to be a pacific island that just got smushed against the then-current coastline. Also remember hearing that Vancouver Island has a lot more in common with New Zealand geology than with North American geology.
Obviously aliens built the Rockies. You know because they're pyramid shaped.
Dang it, ya beat me to it 😂
😂
Insert meme of that Greek guy
This is why i love sci show
Its just pure information about subjects that usually never get on radar.
It keeps your mind thinking
Someone should tell the Rockies they are being mountains wrong.
I just like them cause they give the U.S some extra geographic flavor.
They just wanted a baseball team. I don't 'fault' them.
@Praisethesunson Yea but they prevent the North East from having a warmer climate.
Rocky road, yum!
Not "sev-ear" but "sev-ee-ay". Just for next time. French, and all that. Thanks.
Like they need any more flavour
Considering the beautiful Rocky Mountains are right outside my window, I believe they are actually EXACTLY in the right place. 🙂
Me to. The Crestone Peak shown in the video is within sight of my home and it's right where it should be. It is a mountain among a group of mountains known as the Crestone Needles in the Sangre de Cristo range.
Would second the comment on Nick Zentner's YT lecture regarding the Rockies. Seems by far the most likely explanation and more in line with what we see in every other thrust fault mountain range.
Interestingly the island arc with westward subduction hypothesis wasn't really mentioned here, and since I attended the Rocky Mountains lecture with Nick in Ellensburg last year I'm warming up to that idea. In each of these hypotheses it doesn't even entertain the possibility of westward subduction, which certainly would be enough to propel (pull) the continent westward until it converged with the island arc.
"...which we call that because of a notable lack of volcanoes and volcano-shaped objects" has me rolling. (Also, this is a very engaging and informative video!)
Timestamp: 4:30
I too took issue with this part. Is the Jimenez Caldera not volcanic related/shaped? Or, is it not East of the Rockies?
@@aaronh1372 there is a volcanic field east of the Rockies in New Mexico. The Raton-Clayton volcanic field.
@@jameslay1489 part of the Jemez lineament, Valles Caldera. Same one that I was referencing. The easternmost one. Yet, younger than the Rockies come to find out.
I'm going to suggest glaciers, but somehow I suspect that it would take a LOT of glaciation to grind old volcanoes down to the point they just aren't there any more.
Nick Zentner with Central Washington University has several high-level overviews intended for laymen that goes over a lot of what the current thinking is with the Rockies and the possibly-related Baja BC theories. Highly recommend watching his videos here on UA-cam. I'm nowhere near being a geologist, but I could easily follow along.
His lectures are fabulous! And the current thinking on the formation is both very interesting and makes sense, I really enjoyed his "Eocene A to Z" series. Wish I lived in Ellensberg and could sit in on his lectures.
It seems to me that the Sange De Cristo Mountains of Colorado and New Mexico were volcanic as there are volcanic dikes radiating out from the Spanish Peaks and you have the core of an ancient volcano known near La Veta as the Devil's Thumb. I used to visit this portion of the Sange De Cristos as a kid with my grandparents in the 1970s.
Sangre De Christo. Not Sange De Christo. It means blood of Christ, named for the red color they are likely to reflect during sunsets.
I recall from Geology classes, that the dikes in the Spanish Peaks, and the volcanic rocks that go as far north as Boulder County, are actually remnants of the Rio Grand rift valley in New Mexico.
There is a small extinct volcano east of the Sangres right by I-25 in southern Colorado (the Huerfano), and a larger one east of Raton in New Mexico (the Capulin), part of the Raton-Clayton Volcanic field someone else mentioned. The volcanic dikes are quite pronounced in the Spanish Peaks region.
I love the mystery surrounding my favorite mountain range. Living in a cabin in the Sangre de Cristo range for a summer was one of the best times in my life!
I used to live on Mt. Blanca! Zapata Ridge, right by the Great Sand Dunes!
The rocky mountains being in the wrong place is also a major factor in giving the great plains so many dang tornadoes.
And I've lived in both! Tornado warnings on TV all the time as a kid in Iowa, now I live in technically part of the Rockies and we have hot summers AND cold winters.
It's worth it, though. The place is absolutely gorgeous. I love our "wrong" mountain range. :P
how so? Australia's mountain range is exactly the same as the Rockies in this regard, but no tornadoes on the plains beyond them
@@mehere8038 Fast moving winds flowing over tall, north-south running mountain ranges can induce surface low pressure downwind of the mountain range in a process called lee-side cyclogenesis. This cyclone then pulls together all the ingredients needed to form tornadic storms. Tornadoes would still occur just not to the same degree. In Australia's case, the downwind (lee side) of the great dividing range is in the ocean not over the plains.
@@andrewcovington5898 why would the lee side be opposite in Australia to the US? Winds don't always flow east to west you know.
Wind direction in Sydney right now is NNE, by 3pm it's expected to turn to NE, by 9pm it's expected to turn to NW & bring with it a significant storm. By tomorrow morning it's expected to be WNW & by tomorrow afternoon, straight westerly, where it is predicted to stay for about a week, bringing with it cold air that it's picked up from Antarctica, while on the westerly side of the Great Dividing Range. Westerly winds are FAR more common on the Eastern side of the Great Dividing Range than Easterly winds are. Winds generally come from all directions EXCEPT straight easterly
@@mehere8038 Yes storm systems in southern Australia and in the US generally move West to East as they are being moved along by the West to East flowing jet stream. The leeward side of let's say the Snowy Mountains in New South Wales are to their East when winds blow at them from the West. The great plains in the US are to lee of the Rocky Mountains when winds are blowing over them out of the West.
I just love how quick and concise these possibilities and explanations are presented. We are not slowly dragged through points that are easily comprehended at a rapid manner.
Yes, we are not treated like second graders here. I appreciate that! 🌵👵🐺🖖
So the first theory is basically "im stuck step plate"
Fabulous video. Thank you.
I live west of the Rockies in BC Canada. Never knew there was any mystery about how they formed until now. Learning something new everyday. Thanks @SciShow :)
You know, if I had some geography test and I answered "The Rocky Mountains are in the wrong place", the professor would also probably check to see if I spelled my own name correctly.
Not really. Took some geology courses at Colorado College (in the Rockies): "These mountains are in the wrong place" was seen as a totally legit observation.
Absurd. The mountains ARE where they are, because cause and effect are operating.
It's not the mountains that are the problem, but the inability of geologists (thus far) to present a complete, water-tight theory (or related group of theories) that accounts for all the puzzling observations.
If you want to make the Rockies really weird. The valley I grew up in was a valley but it has no mountains visible technically other than the SanJuans. Nearby the town I lived in is a igneous mesa caused by a basalt capstone
We should appreciate formations like this. It gives rock nerds something to argue about.
Love this! I wish the explanations were animated so I could visualize it even better.
What I’ve heard (and think is true) is the last one, the flat-slab. Eventually, for some unknown reason, the Farallon plate (the flat slab in this case) suddenly sunk, in a process known as slab rollback. This let magma leak into the overlying Rockies creating a bunch of volcanoes, like Yellowstone, Dotsero, the ones in Arizona and New Mexico, and the La Garita caldera.
I highly recommend a UA-cam lecture from earlier this year by Nick Zentner, called How the Rockies Formed. It goes over the recent data gathered and how flat slab subduction is less likely, and he shows the new hypothesis.
@@amacuro Thank you for the input, I will have to look into this later.
Except that - in the case of Yellowstone - there is abundant evidence (Including a sequence of older "dead" caldera progressing westward, visible also on LIDAR maps) indicating that North America migrated westward over a persistent hot spot, interpreted as a stable mantle plume. And the vulcanism spans recent millions of years, post-dating the orogenies.
@@anorthosite I think they were separate events. As I recall from Zentner's many video talks (see the A-Z series on Baja-BC), the collisions between North America, Insular and Intermontane terranes that created the Sevier and Laramide orogenies started around 100-80 Ma. The collision with Siletzia that created the Idaho batholith and related magmatic activity was around 50 Ma.
During that entire time, North America was moving westward over the Yellowstone hotspot. The hotspot was offshore at 50 Ma. And speaking of slabs, there's an anomalous slab located two thousand km beneath New York state, which could be the broken remnants of either North America or a Pacific plate that was subducted and then pinched off.
You know, Utah AND Idaho have a plethora of volcanic activity west of the Rockies.. Craters of the Moon in Idaho and pretty much the whole of the west desert in Utah as well.. there are quite a few cinder cones in Southwestern Utah.. So, there’s plenty of volcanic activity in recent past…
Big element left out of this video. All of the volcanic hot springs spread throughout the mountains. Speaking specifically on British Columbia, because that's where i was born and raise. Off the top of my head there is Harrison Hot Springs just outside of Metro Vancouver. You have Halcyon, Ainsworth, Fairmont, Nakusp, Banff, Radium, and Skookumchuk. There are dozens upon dozens more.
So cool! Always kinda wondered about this.
My bet is on the Baja BC model. Makes the creation of the Rockies more like the Himalayans creation. Definitely need to have something massive hitting the North American Tectonic Plate to create mountains.
If you found this interesting and want a more detailed explanation of the “new model” watch the video “How Did The Rocky Mountains Form” from Nick Zenter. Great presentation of how the mountains could have formed and a more complete explanation of the geology of western NA.
I attended Nick's Rocky Mountains lecture in Ellensburg last year and since then I've really warmed up to the hypothesis of a stationary island arc sitting over _westward_ subduction, which certainly could've provided the impetus for the NA continent being pulled in that direction -- and once converged began thrust-fault movement and enough compression to start another orogenic event (Laramide).
Thanks Stefan, I love exploring earth mechanics and how things work. I never thought about why the Rockies are where they are. Very interesting :)
A good, concise presentation!
Doesn't that mean the Appalachian mountains are similarly odd? They may be older, but they're even more centered on the plate they're on.
They are the remnants of a much older collision. Parts of it extend into Canada (Newfoundland) amd the Scottish Highlands.
They're centered because of the Mid-Atlantic Ridge. New crust formed between the mountains and the rift, giving the appearance of a mid-plate mountain range. Before the breakup of Pangea, the Appalachians, Little Atlas (Morocco), and The Scottish Highlands would have formed the Central Pangean Mountains centered over the plate boundary.
Not really, Appalachians are fairly normal continental margin crumple zones when other continental land masses smash into the core NA Kraton without subduction and then rift apart. Nearly every Kraton has similar mountains around it, Baltica, Amazonia, Arabia, Austrialia. It's just that the rifting process stretches and sinks the land at the rift point due to the denser oceanic crust coming up through the rift, follow that will errosion of the mountains into the sea and create a smooth coastal plain and you get what we call a passive continental margin.
I take the statement of the rockies being in the middle of the continent a bit skeptically. They are mainly the western third, then the great plains, and finally the Appalachian mountains and companions. I find the Appalachian fascinating since they formed on Pangaea. Either way, it is fascinating as we find out more.
weren't they part of the atlas mountains in africa when pangea was around and just have withered away
I'm sure all these events happening at once is rare.. but it seems the Rockies might be that perfect collision
As a geologist that has been studying volcanoes and plate tectonics since she was four as well as grew up in the Colorado Rockies, I have since come up with a couple of alternative hypotheses for this.
My favorite is based on the "shape" of the continental plate. Nearly every geological diagram presents a tectonic plate as "flat". However, they are far more similar to that of a broken egg shell in that they are more "curved" than anything. So what happens when you put alot of weight on either side of most already curved objects? They tend to crack, break, lift up and start to splinter. So the "weights" of the Pacific and Atlantic plates are likely causing the Continental plate the slowly buckle in the weakest point like an old piece of wood.
Originally from Alberta. Living in Quebec now. This video just made me miss the Rockies so much. So god dam incredible and beautiful
I like rocks
You lot should do a collaboration with the Rock guy, Nick Zentner. He's very good.
His presentation about the formation of the rocky mountains gave me SO many questions about how changing theories about the Farallon plate may impact ideas about the Mid Tertiary Ignimbrite Flare Up
When I drove through nevada and utah earlier this year, I had the same question that this video discusses, and it’s absolutely CRAZY that we don’t even know why yet!
In a hot tub so you KNOW why a bit of the watet surface on 1 edge is a bit higher from the water jetting up there more? Random TURBULENCE like in molten earth maybe made the Rockies there... The earth is 5000 miles wide so itd take minor variation in turbulence to make the 2 mile high Rockies. Scientists don't like to admit random stuff is probably the cause of weird flukes in geology. Or who knows..
Just got the Answers magazine in the mail last week and they did an entire article on this subject. Very interesting. Pretty simple and happened quickly.
Never thought I'd see an episode on the Laramide, should do one on the Ancestral Rocky Mountains, also a weird one. Great stuff
The Canadian tectonic plates got confused because the instructions used the imperial system.
I am blessed to see the Rocky Mountains everyday of my life. Love hearing the different hypotheses on how they were created
My mum did her dissertation on the Laramide Orogeny and it's wild. She said it caused an uproar in the geology department of her university lol. I definitely think there's a plate element to it, and I think since a lot of the Colorado plateau is sandstone, it was much easier to lift because it's lighter than the granite and basalt. As far as the northern and southern Rockies, chemistry and plates built those. Tough one cos there are so many variables and stuff.
Nick Zentner (on UA-cam) has a ton of great content on this, and other interesting geology!
Or as we see in new zealand both the plates had continental and oceanic components. Resulting in a mixed boundary.
New Zealand is part of a microcontinent called zealandia...
Yeah you can get very ambiguous environments though a more analogous analog of mixed boundary zones would be the Sunda trench system where the Australian continental self is getting subducted with geochemically Australian sediments actually ending up accreted melted and erupted into Indonesia as the volcanic arcs are gradually getting welded to the Australian plate as the underlying slab finally breaks away under the increasingly more buoyant and continental material.
Zealandia is itself a complex geological story but its not quite the same processes as what are going on in these other situations
@@starfury1 what makes it "micro"? I know it's the world's smallest continent, but it doesn't seem small enough compared to the others to warrant the tag of "micro" to me. I mean Europe is less than 1/4 the size of Asia, while Zealandia is half the size of Europe, so it's not like it suddenly drops off & becomes proportionately smaller than the variability between other continents sizes
I'm so glad you included Pikes Peak in your photos ❤ that's my backyard ❤❤❤
So glad that someone besides me has finally noticed how the bumpy parts really are in the wrong place, would you mind pushing the playdough lumps around till that's been fixed?
The Appalachians aren't particularly close to the coast, either, but I think that has more to do with them forming before the coast even existed. (I mean, technically, a piece of them wound up on the opposite side of the ocean.)
They formed during the creation of Pangea two colliding tectonic plates, which subsequently split apart. There is evidence on both sides of the Atlantic in respective mountain ranges
@@PlayNowWorkLater Is this the case for The Great Dividing Range too?
@@mehere8038 if you’re referring to the great dividing range that was as a result of Australia colliding with New Zealand, then yes. That collision happened around the same time, 300 million years ago, which is around the same time the Appalachians were being formed. Pangea was a pretty humongous landform and a number of collisions generated a number of different mountain ranges that are still around today. Pretty cool stuff!
@@mehere8038 yes! Actually
@@mehere8038 if you’re referring to the great dividing range that was as a result of Australia colliding with New Zealand, then yes. That collision happened around the same time, 300 million years ago, which is around the same time the Appalachians were being formed. Pangea was a pretty humongous landform and a number of collisions generated a number of different mountain ranges that are still around today. Pretty cool stuff!
I’d really love to know if this is related to how all of the highest rocky mountains in the continental US are so close to each other in height. It’s mysterious, it’s like there was a height limit!
"it’s like there was a height limit!" - it's called _gravity_ .
@@TheDanEdwards Better tell that to the Himalayas, which are notably just a wee bit taller than the Rockies. Last time I checked, at least.
@@TheDanEdwards Why talk when you have no clue what you are talking about? The Himalayas are far greater than the Rockies in height, same gravity.
@@kylerBD While we're in the pedantry corner: if I remember correctly, the force of gravity experienced in the Himalayas is actually greater than that experienced in the Rockies since there is technically more...earth? under them. So the gravity isn't actually the same, but ironically greater in the taller mountains.
If you go into the western part of the Great Plains, you will find another height mystery: on average, the prairie in this region adjacent to the Rockies is about 1500 - 1800 meters high. This is perplexing because it implies that the prairie itself underwent uplift along with the mountains but somehow retained its flat profile, and it defies conventional orogenic processes.
Everywhere I travel, I try to learn something about the geology of the area and what might currently be occurring there. It taught me that there’s no single, unified process description that addresses everything we see and experience on the planet…
Well said!
This is interesting as I grew up and attended grade school and college right on top of the Wasatch Fault-line in Utah.
Check this Video out by Nick Zenter, A geology Professor at Central Washington University. He discusses a possible collision with a large island and evidence for it.
ua-cam.com/video/I9Xk1O17dzg/v-deo.htmlsi=1dhc8hs_gcQf6-OD
There are many exotic terranes, and Nick covered some of them. He's also touched on the Rocky Mountain orogeny but he admits there are many puzzling aspects.
I wonder if they've taken into account the two hotspots that were/are under North America. The first being Yellowstone, and the second the one that created the Ozarks and is now under Bermuda?
the hot spot came into effect alot later after the rockies were formed
Visiting many times, I've been fascinated with the *extreme compression of faultline rock NE Storm Mt. Big Cottonwood Canyon in N. Utah. Talk about pressure!
Fascinating, thank you.
Spent a week in August studying "Transpressional Collison" in Idaho ( W I S Z ; Western Idaho Shear Zone ). Rock evidence of shearing/uplift/ northern movement from northern Utah to northern Canada.Currently there is clockwise rotation in the PNW and in the W I S Z.The " centers of rotation
' are Pendelton Oregon and Orofino Idaho respectively.
Did you actually attend the Penrose? If so I’m jealous.
I was there 8-14 thru 8/17 a group of us did a two day field trip with Basil Tikoff, Stacia Gordon, et al.This was a " warm up " of sorts for the Penrose.Nick Zentner and Sabir Nooh ( actual field lectures recorded ) have excellent YT vids online.
@@sidbemus4625 I would love to have attended the dress rehearsal.
what about the effect of the Western Interior Seaway? It's existence coincides almost exactly with the period in which the rocky's formed? could the depression of the crust in the region of the seaway caused an impediment that forced crumpling and uplift at the boundary?
I believe the Western Interior Seaway is thought to have formed as a result of the uplift of the Rocky Mountains generating depression in the adjacent crust.
The last one is the one I always heard about, the subduction of the Fallon Plate created all the mountains and valleys west of the Rockies. Initially the land that's now the Rockies was the coast and the "crumpling" affect with the great basin, Sierra Nevada mountain range, cascades and the various valleys in CA, Oregon, and even the smaller ones in Washington are all due to the shallow descent of the Fallon plate, with smaller ranges like the coastal ranges being islands that collided with the land essentially scrapping it off the plate. That's atleast how I've understood it
Live in Colorado in the mountains (San Juan’s). We find shells here and sea life fossils all the time. Also we have remnants of volcanoes all over the place, the the south, southwest and southeast mainly.
My professor explained it as the Jaun de Fuca plate having a bunch of islands that crashed into the North American plate as it was subducted under. That the north america plate was made wider than it originally was by this.
Short and sweet.👍
That's what I was told too! By my high-school freshman earth science teacher. He was a brilliant guy.
Can this accumulation account for the distance from the current edge of the North American plate? I can see it as creating California's main geography of Coast Ranges-flat valley-Sierra Nevada range but the Basin and Range region?
@@LadyAnuB Basin and Range is the result of a built up plataue that basically collapsed under it's own weight and widens the continent. Think of it like a shelf of books that flop over, widening and lowering itself and making a saw tooth pattern on top.
Yes some land was added to N America as islands hit, basically west of Idaho and west of Nevada. But the Rockies still form too far east, they formed starting in Colorado not Nevada or Arizona ..... Imagine if Japan and Taiwan got smashed into Asia 90m years ago, that's basically what the 3 coastal states and British Colombia are, new land added recently to 3b year old N America.
The Adelaide Geosyncline Orogeny (AKA The Adelaide Hills and Flinders Ranges, South Australia) was formed from a failed rift valley filling with sediment over the better part of a billion years before being thrust up into a mountain range in the Cambrian period. Perhaps elements of a similar event went into the formation of the Rocky Mountains? I don't know enough about North American geology to say for certain, but it's worth a contemplation.
The nazca & juan de fucha were the same plate with a mid ocean ridge. Na ran over, the ridge elevated the content, and the leading plate fell off in ribbons. An upwelling extruded Colorado plutonic Laramied's. Utah/idaho strikeslip mountains happened with the Colorado plateu on top, at the time of uplifting. Then the rifting as each ribbon of oceanic plate fell under. Expanding the land mass.
This video needs to be coupled with a video on the formation of the Great Basin. I believe there’s a correlation there.
The coastline of North America wasn't always where the coastline of North America is now... Once upon a time it was closer to Idaho and Eastern Washington... Google three things Nick zentner... Slab window... And exotic terranes
I think the real mystery is the Pacific oceanic plate and how it forced the Juan de Fuca's subducted remnants to become the Rocky Mountains, which is really just a multitude of parallel mountain ranges with a high amount of historical volcanic activity to the West but a relatively low amount East of the range and all happens to be centered around the last vestiges of the Juan de Fuca.
What I wonder is what really drives the Pacific plate and whether it is truly one singular plate or a conglomerate of thick, interlocked plates that behave as one due to their tension.
After the Juan de Fuca subducts completely in 17.5 million years or so, maybe we will see the Pacific plate break up and show its true underlying structure.
Well, *we* won't see it
Literally right before you mentioned the volcanic fields in BC and NM, I was thinking the same thing (at least about NM). I remember driving through them from Clayton to Raton - and thinking - wow, what are these doing here since they are right before the the Front Range of the Rockies. The only volcanic activity I was aware in the Rockies was Yellowstone - and I think that is for a different reason.
The shoreline used to be at spokane. A micro continent docked pushing up mountains east of spokane.
I love to hear about your orogenous zones.
Except there is one really big volcano instead of many. That's Yellowstone.
The western part of the north American plate is pretty busy: terranes, the faralon, cocos, jaun de fuca and Pacific plates, subduction, transverse... weird stuff. Neat stuff.
Isn't Yellowstone a hotspot under the plate? Hotspots exist irrespective of the plate tectonics going on above--though it brings up the good point of what effect a massive hotspot would have on the Siever and Laramide orogenies.
@@Mockingbird_Taloa yellowstone is a hotspot, unrelated to this orogeny
Actually, the southwest is peppered with massive calderas from 50mya to 20mya (rounded). It's known as the mid tertiary ignimbrite flareup. They are manly centered in Nevada, but happened in Nevada, Utah, Colorado, and Arizona. More fascinatingly is they appear to have happened in 3 bursts, with the oldest in the North and progressing to the South. It's often attributed to slab rollback and extention.
The Wah Wah Springs Caldera was a absolutely massive eruption and discovered within the past 20 years. It is one of the largest known volvanic eruptions, with over 5000cu km of material erupted.
Addition: I almost forgot about the kimberlite "arc' east of the rockies as well, such as the Jackson Volcano (95mya) in Arkansas, which runs in a North west direction all the way into Canada. It has an official name but I cannot recall it ATM. Maybe someone can help out.
The Rockies, it's formation, the volcanism on both sides, and now with Tomography and discovering slab walls (Karen Sigloch) it's clear that we are missing some large peices to the puzzle still.
That's a mantle plume which is un-related to plate boundries, it literally just stays in one place as North America moves over it, similar to the Hawaiian hot spot.
@@primarytrainer1 It might be less unrelated than you might think based on what I've learned from Nick Zentner's recent Baja BC A to Z series (as well as the previous year's Crazy Eocene A to Z series). Notably from seismic tomography we can see the locations of subducted slabs in the mantle in the form of cold high density downwelling slabs and walls as well as lower density upwelling zones like hot spots(there are multiple types) and Mid Ocean Ridges, Yellowstone appears to underlie the upwelling lineaments contiguous with the Juan de Fuca Ridge and the East Pacific Rise in a triple Junction like configuration not to dissimilar to what we see in Iceland and to a lesser extent the Azores.
From Igneous petrology Siletzia has been fairly conclusively linked to the Yellowstone hotspot track as has the snake river plain volcanism See Petrogenesis of Siletzia the world's youngest oceanic plateau (www.sciencedirect.com/science/article/pii/S2666277920300046#sec0021).
The subducted slabs and the associated slab walls notably are all to the north and east of this low sheer velocity lineament structure in the solid mantle which added with the very different character of the underlying mantle on each side of the discontinuity(i.e. the north and eastern sides involve colder presumably older more continental material while the mantle beneath the Colorado plateau and basin and range is basically oceanic in characteristics.
The shape of this boundary also lines up pretty well with the phases of the Tertiary ignimbrite flair up @jasonbiskie672 mentioned where I should note the zones of volcanism notably also are parallel with metamorphic core complexes of effectively the same age so it seems quite believable that both could be a natural consequence of subducting a deep mantle rooted upwelling ridge line that subsequently has stalled NA while slab pull along Cascadia and Mexico has kept pulling and unzipping the former mountains and accreted arc terrains over time. In this case you likely had the formation of a Himalayan style mountain range which has as the subducted ridge has passed beneath it gotten pulled apart like an accordion exposing the deep metamorphic core complexes and the the still partially molten batholiths formed from rock melted by the huge potential energy of some 15+ kilometers of overlying rock weighing down on them. Rapid decompression thus leads to rapid melting as you move down the pressure axis of the PT diagram going from solid to liquid at a given temperature meaning lots of high pressure magma now far closer to the surface where they can much more readily erupt.
There is lots of magma below the Himalayas there is just so much material that intrusions almost never reach the surface to cause volcanism(the last documented volcanic eruption in the Himalayas was in the Tibetan side during the 1940's).
Maybe the subducted Farallon plate was much bigger than previously thought
Back in 2010 when the Fukushima earthquake happened, the plate moved 30 feet in just a few seconds.
We can sail, we can sail with the Orogenic Float
We can sail, we can sail
(Sail away, sail away, sail away)
...is it at all possible this puzzle also comports with the huge volcanic features generally west of the Rockies? I read a paper about Mt. Paektu. It had a lot to say about the peculiarities of the area around it, but more of a kind of thermal/magmatic abscess created by the way the pacific plate had been sheared or kinked. There was also the idea that Mt. Paektu sits at the intersection of two volcanic arcs, and is fed heat from both allowing it to grow much larger than one would expect to find so far from the plate boundaries.
Funny enough there is a simple answer to that and is explained by the fifth theory not explained in this video. It is simply that the subducting plate was was not subducting below NA, instead it was going the opposite direction and subducting under a micro continent. NA then impacted that micro continent forming the rocky mountains in a continent-continent collision! This impact pinched off the oceanic crust plate between them in the Mantle and we can now detect the remnants of it under new york today! (NA continued to move over the mantle). I would suggest watching Nicks video lecture on the rocky mountain formation. It goes over this and is very fascinating and based on the latest evidence is the best theory to explain the formation of the rockys.
@@lightside33333 I very much appreciate that recommendation, I'll track it down, Thanks!!! 😉🤘
It's mainly left over root system from the giant trees. Colorado River used to flow the opposite way like a straw from the ocean leaving places like the salt flats to eject the salt.
You are posting mythology.
I live a block away from the Rockies. Our mountains here in northern Utah are weird too where they shoot straight up, no foothills really. So I walk a block and I'm in the mountains. It's gorgeous. The mountain (Ben Lomand) I live by was the old Paramount Pictures mountain actually. That same mountain you can see a fault line called the Wasatch fault. A couple years ago we have an earthquake that was 5.6 and they discovered a new fault line they never knew about. There are always new things to discover!
Shiny rocks? (Crow looks around eagerly)
We have a large caldera centered in the riverbed of the Rio Grande at Albuquerque, which conceals a fault line. Just saying that with the northward shift of the magnetized rock, perhaps this caldera may have planted the seed for the upthrust of the range we call the Rockies
The Valles Caldera, if that's what you're referring to, meets at the intersection of the Rio-Grande Rift and the Jemez Lineament. The Jemez isn't active but it runs East-West, and the Rio-Grande runs North-South but the movement along the fault is East-West. The Rio Grande Rift is much younger than the Rockies, so therefore Valles also has to be younger than the Rockies.
What is the name of the caldera you're talking about? I know there are many in New Mexico.
I was wondering about Jemez, for it is "volcanic shaped" and east of the Rockies. Did not realize it was younger
Geology Hub has a good video on the caldera
@demoman1596sh we live up on the West Mesa near the rim of the Albuquerque basin, where the cliffs are imbued with black lava deposits. The Sandia crest towers over the city to the east, 10,000 plus ft in altitude. en.wikipedia.org/wiki/Albuquerque_volcanic_field
I would say that there is likely more mechanics at play. I think the flat-plane subduction hypothesis is probably one of the principle mechanics of the formation process, though certainly not the only one. While it is true that there are plenty of places in California with weak enough crustal geology to have bunched up there, California is also home to a the Franciscan formation which, by its nature, has rather dynamic hardness and viscosity properties which may have played a part in disrupting what we would otherwise expect to see. These two mechanics mixed with a faster pace of, essentially, oscillating tectonics likely play a considerable part in Rockies formation. It should also be noted that there is a rather large super-volcano complex smack in the middle of all this. It may be that the large reservoir of magma associated with Yellowstone is actually a symptom of flat-plane movement, pushing viscous magma like a subterranean river. I could, however, be wildly incorrect. As such, I suggest we cut a big ol slice of the crust open and check it out. :)
There is also the question of the McKenzie range on the eastern edge of the Yukon/western edge of the Northwest Territory. The formation composition suggests that it should be part of the American section of the Rockies but is displaced hundreds of miles northwards. I read some about it last year and as of that reading, it’s current location is something of a mystery. I would like to agree with the praise for Nick Zenter and his various lectures and videos. What a great teacher. His enthusiasm is as great as his depth of knowledge and engagement with his subject. Wonderful sense of humor and he can keep his audience engaged with no more visual aids than a blackboard. His students at Central Washington university and those who attend his community lectures are privileged indeed.
Summary: We have no idea how the Rocky Mountains were formed.
Yeah, but they're in the wrong place.
This makes me think of the Ural mountains. Is there a plate boundary there?
Baltic Plate and Eurasian Plate
@primarytrainer1 can't find it on any plate boundary maps. They all show Eurasia as a single plate. Minus India and the Arabian peninsula of course, and aperently a section of far eastern Russia is part of the North American plate on many of the maps.
@@primarytrainer1 Isn't the Baltic plate just a micro plate that is considered an extension of the macro Eurasian Plate?
If you look at the wasatch front in utah, you see three directions of long term pressures in the stratigraphy. East/west pressure, as well as the north south folding of the layers. also this north/south pressure shows up as the uintah range and basin piling upward. Directly north of this is Yellowstone.which thins the crush as well as adding upward pressure for 100s of millions of years. I’m not an expert, but sometimes the simple observations are the best explanation.
Thanks!
Could it be the slow erosion of the Appalachian mountains literally changing the buoyancy of the North American plate, making it tip onto the Pacific plate. And it buckles/crumples in the weak spot in this situation, somewhere in the middle of the "beam". Once it breaks, that's the weak spot and it continues to fold from there.
Could be
Appalachian mountains deposited mostly to the west, so I don't think it would have changed the buoyancy of the plate much other than to somewhat more evenly distribute the load. Sediment from the the Appalachians and Ouachitas traveled mostly east-west to be deposited in what's now the Great Plains--water (and sediment) only started flowing west to east once the Rockies were uplifted past the level of the Gulf
The melting of the ice sheets had an effect on isostasis more recently.
Continents and mountains float in the mantle, when a mountain errodes the plate rises higher in the mantle partly canceling the lowering of land that errosion is causing. The plate is flexible enough to have some parts rising and other parts sinking because it is overall a very thin object just a new miles thick but thousands across. The mental analogy you should have is something like a pot of boiling water on a very uneven burner with oil floating on top which is pushed into shapes by the convection, mountains are then just ripples induced in the oil as they crash together or are pushed.
Here in Utah, we say Sevier differently so I thought he had said “severe orogeny”. 😂 I’ve heard pronounced “seav-er”. I’m not sure what the original is, but I do get that language is very dynamic and regional and it’s only pedantic people who think it should be pronounced one and only one way.
as someone whos never heard of the Sevier Orogeny, I also thought he said "severe" lmfao
I'm here in Texas. When I read the name, I thought it should have been sounded as "sev-ē-ā".
I guess closer to a French pronunciation?😮
@@loraweems8712 My take on the pronunciation also. But Im Canadian... so tend to French pronunciation, when in doubt.😊
According to Wikipedia: The “severe orogeny: is named after the Sevier River in Utah and is pronounced "severe". The Sevier River is in turn derived from the Spanish Río Severo, "violent river".
@@Obscurai Thank you!
I sometimes forget to use Google!
"Flat-Slab Subduction" could be a really cool name for a Metal band!🤘🎸🔥
Thanks SciShow for the AWESOME content!!!🤘🥰
There are many mountain ranges around the world that are not on fault lines between tectonic plates. The Scandinavian mountain range (which makes up a huge part of the border between Sweden and Norway) is one. The thing is that the plates haven't always looked like they do now. Mountain ranges withing tectonic plates suggest this is where previous plates crashed into each other, merged and formed new, bigger plates. Over the course of Earth's history, there have been at least seven different supercontinents and subsequent plate movements. A lot of plate changes in other words.
So the most likely answer is that the "Rocky Mountain Range" isn't a single range, but a whole bunch of different mountain ranges, all in approximately the same line, an potentially all caused by different events. Y'know, sounds as legit as pretty much any other answer.
Or, there was one unimaginably catastrophic event that caused them to form all at once.
You mean like the Sa Juan Range of SW Colorado, the Front Range, the Never Summer Range, the Medicine Bow Range, etc. It likely means we don’t know, we think we do, but we don’t.
@@reijishian2593Like Creation?
Honestly let's all just be rational here and understand it's actually a very simple solution. It's aliens, obviously.
I live along the Wasatch front on the western face of the rockies in Utah. There are dozens of prehistoric volcanos west of the rockies here as well. 💯
Growing up in Calgary I never ever doubted the placement of the Rockies. To see them everyday and visit them multiple times every year is bliss. The hot springs in Banff have always been a fixture in my family's lives.
The Rocky Mountains are right were they are supposed to be by design...damn they are beautiful.
There are things even more interesting to tie into this. There was a large but somewhat shallow ocean in the middle of the continent. There are three chunks of protocontinents which meet up with the Continental Craton near the Northern border of Oklahoma and in that same area the sedimentary basin is somewhere in the 30 thousand feet deep scale. AND there are two remnant ash cones in Eastern Kansas (eroded flat) and an igneous intrusion near the small town of Piedmont. As of my younger days these had not been seriously researched do to being on private property (and attempts to get permission failed) and there is no great amount of oil out there so little work was ever done. 30 years ago while I was in school I approached one of the top geotectonics people in the country (at that time) and he did not have an idea either. I am no longer in that area (very far away 😃) or I might have looked into it myself.
The arrow in the thumbnail is scarily accurate for where I live.
I always assumed that the western interior seaway was between two plates and that all the mountains formed when the seaway closed... how have I never noticed there isn't a plate boundary on tectonic plate maps.
The simplest answer which also seems to be consistant with what has been found in NE China is a fold of the plate. Why a fold, can't say but might be worth concidering. Now for me to watch the upload.
Ahh, but there is plenty of fossil evidence in the Southern Canadian Rockies ... fossils of ancient Ocean life.
Furthermore, the sedimentary rock that makes up the Canadian Rockies is your evidence of a body of water between the Rockies and the Ocean plates ... sedimentary rock is just that ... sediment that has been formed into rock ...
I studied with a Canadian geologist that specialized in the Canadian Rockies and the mountains of British Columbia.
The Prairies were an inland sea during the Cretaeous. Bruce the Mosasaur in Morden MB is evidence of that.
Some animated illustrations to go along with the different hypotheses would be very helpful
West of the Rockies are also Yellowstone and Mt. St. Helens, both of which are areas of past volcanic activity.